Influence of 18F‐fluorodeoxyglucose‐positron emission tomography on computed tomography‐based radiation treatment planning for oesophageal cancer

The addition of positron emission tomography (PET) information to CT‐based radiotherapy treatment planning has the potential to improve target volume definition through more accurate localization of the primary tumour and involved regional lymph nodes. This case report describes the first patient enrolled to a prospective study evaluating the effects of coregistered positron emission tomography/CT images on radiotherapy treatment planning for oesophageal cancer. The results show that if combined positron emission tomography/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone. For this patient, a geographic miss of tumour would have occurred if CT data alone were used for radiotherapy planning.     

18F‐Fluorodeoxyglucose positron emission tomography/computed tomography for the detection of recurrent bone and soft tissue sarcoma

BACKGROUND:

The clinical utility of modern hybrid imaging modalities for detecting recurrent bone or soft tissue sarcoma remains to be determined. In this report, the authors present a clinical study on the diagnostic accuracy and incremental value of integrated ¹⁸F‐fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F‐FDG PET/CT) in patients with a history of sarcoma who have clinically suspected disease recurrence.

METHODS:

Forty‐three patients who had a history of bone or soft tissue sarcoma and had documented complete remission underwent ¹⁸F‐FDG PET/CT. Image analysis was performed independently for ¹⁸F‐FDG PET (n = 43) and for contrast‐enhanced spiral CT (CE‐CT) (n = 30) by 2 separate readers, whereas combined ¹⁸F‐FDG PET/CT (n = 43) images were analyzed in consensus by both readers. Imaging findings were rated on a 5‐point scale and finally were reported as malignant, benign, or equivocal. Imaging findings were validated either by histopathology (n = 24) or by clinical follow‐up (n = 19).

RESULTS:

¹⁸F‐FDG PET/CT had greater sensitivity and specificity compared with CE‐CT alone (94% and 92% vs 78% and 67%, respectively), resulting in significantly greater accuracy (93% vs 73%; P = .03). ¹⁸F‐FDG PET/CT was particularly superior regarding detection of local recurrence or soft tissue lesions (sensitivity and specificity: 83% and 100% vs 50% and 100%, respectively) or bone metastases (100% and 100% vs 85% and 88%, respectively).

CONCLUSIONS:

¹⁸F‐FDG PET/CT had greater diagnostic accuracy in the detection of recurrent bone or soft tissue sarcoma compared with CE‐CT alone. The detection of local recurrence was the most evident advantage of ¹⁸F‐FDG PET/CT over CE‐CT. Cancer 2013. © 2012 American Cancer Society.     

[F‐18]‐fluorodeoxy‐D‐glucose–positron emission tomography response is associated with outcome for extremity osteosarcoma in children and young adults

BACKGROUND:

Response to neoadjuvant chemotherapy is 1 of the most powerful prognostic factors for extremity osteosarcoma. [F‐18]‐fluorodeoxy‐D‐glucose–positron emission tomography (FDG‐PET) is a noninvasive imaging modality that is used to predict histopathologic response. To determine the prognostic value of FDG‐PET response for progression‐free survival (PFS) in osteosarcoma, the authors of this report reviewed the University of Washington Medical Center experience.

METHODS:

Forty patients with extremity osteosarcoma were evaluated by FDG‐PET. All patients received neoadjuvant and adjuvant chemotherapy. FDG‐PET standard uptake values (SUVs) before neoadjuvant chemotherapy (SUV1) and after neoadjuvant chemotherapy (SUV2) were analyzed and correlated with histopathologic response.

RESULTS:

The median SUV1 was 6.8 (range, 3.0‐24.1), the median SUV2 was 2.3 (range, 1.2‐12.8), and the median SUV2 to SUV1 ratio (SUV2:1), was 0.36 (range, 0.12‐1.10). A good FDG‐PET response was defined as anSUV2 <2.5 or an SUV2:1 ≤0.5. FDG‐PET responses according to SUV2 and SUV2:1 were concordant with histologic response in 58% and 68% of patients, respectively. SUV2 was associated with outcome (4‐year PFS, 73% for SUV2 <2.5 vs 39% for SUV2 ≥2.5; P = .021). Both the initial disease stage and the histologic response were associated with outcome.

CONCLUSIONS:

FDG‐PET imaging of extremity osteosarcoma was correlated only partially with a histologic response to neoadjuvant chemotherapy. An SUV2 <2.5 was associated with improved PFS. Future prospective studies are warranted to determine whether FDG‐PET imaging may be used as a predictor of outcome independent of initial disease stage. Cancer 2009. © 2009 American Cancer Society.     

18F‐fluorodeoxyglucose and 11C‐acetate positron emission tomography are useful modalities for diagnosing the histologic type of thymoma

BACKGROUND:

The objective of this study was to clarify the usefulness of positron emission tomography (PET) using¹⁸F‐fluorodeoxyglucose (FDG) and carbon 11‐labeled acetate (AC) for predicting the histologic types and tumor invasiveness of thymoma in a multicenter study.

METHODS:

Forty thymomas were examined using both FDG‐PET and AC‐PET before surgery. The histologic types were type A in 1 thymoma, type AB in 12 thymomas, type B1 in 11 thymomas, type B2 in 7 thymomas, type B3 in 6 thymomas, and type C in 3 thymomas. Tumor invasiveness was assessed by pathologic tumor stage and was identified as stage I in 17 tumors, stage II in 17 tumors, stage III in 4 tumors, and stage IV in 2 tumors. FDG and AC uptake was measured as the maximum standard uptake value (SUV).

RESULTS:

The FDG‐SUV in type C thymomas was significantly higher than that in the other types (A‐B3; P = .001 – P = .048). The AC‐SUV in type A/AB thymomas was significantly higher than that in the other tumor types (B1‐C; P < .001 – P = .002). All 3 type C tumors had an FDG‐SUV ≥6.3, and all 13 type A/AB tumors had an FDG‐SUV <6.3 and an AC‐SUV ≥5.7. All 17 thymomas that had an FDG‐SUV <6.3 and an AC‐SUV <5.7 were type B1, B2, or B3. Neither the FDG‐SUV nor the AC‐SUV differed significantly between the stages I/II tumors and stage III/IV tumors.

CONCLUSIONS:

Although neither the FDG‐SUV nor the AC‐SUV can predict the invasiveness of thymomas assessed by tumor stage, they are useful for predicting histologic types of thymoma. Thymomas with an FDG‐SUV <6.3 and an AC‐SUV ≥5.7 almost certainly are types A/AB, which is of considerable prognostic and management significance. Cancer 2009. © 2009 American Cancer Society.     

Detection of occult bone metastases of lung cancer with Fluorine‐18 fluorodeoxyglucose positron emission tomography

Accurate staging of cancer has a critical role in optimal patient management. Fluorine‐18 fluorodeoxyglucose positron emission tomography (FDG PET) is superior to CT in the detection of local and distant metastases in patients with non‐small cell lung cancer. Although Tc‐99 m methylene diphosphonate (MDP) bone scanning is well established in the evaluation of bone metastases, there are conflicting reports on the use of FDG PET in the evaluation of skeletal metastases. We report on a patient with locally advanced lung carcinoma in whom FDG PET accurately identified previously unsuspected widespread asymptomatic bone metastases (bone scan and X‐rays negative, confirmed on MRI). Assessment of glucose metabolism with FDG PET might represent a more powerful tool to detect bone metastases in lung cancer compared with conventional bone scans.     

The clinical application of 18F‐fluorodeoxyglucose positron emission tomography to predict survival in patients with operable esophageal cancer

BACKGROUND:

Metabolic tumor activity using ¹⁸F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) was believed to have a predictive value for patient outcome in malignancies. The objective of the current study was to assess the prognostic effectiveness of the highest standardized uptake value (SUV) in the primary or regional area (peak SUV) and the number of PET‐positive lymph nodes in esophageal cancer.

METHODS:

The authors retrospectively reviewed their experience with 184 consecutive esophageal cancer patients imaged preoperatively using FDG‐PET scanning.

RESULTS:

The median peak SUV was 4.5 (range, 1.4‐21.9). The survival curve was analyzed using the median peak SUV as the cutoff value. Comparison of each group and clinicopathologic characteristics revealed significant associations between peak SUV and each of the following factors: tumor status (P < .001), lymph node status (P < .001), metastatic status (P < .05), stage of disease (P < .001), number of PET‐positive lymph nodes (P < .001), and the number of histologically positive lymph nodes (P < .001). The 5‐year overall survival (OS) rate for patients having FDG uptake with a peak SUV ≥4.5 was 47% and that for patients with a peak SUV <4.5 was 76% (P < .0001). On multivariate survival analysis using the Cox proportional hazards model, peak SUV and the number of PET‐positive lymph nodes were found to be independent predictive factors for OS. The number of PET‐positive lymph nodes was a single prognostic factor predicting both disease‐free survival and OS.

CONCLUSIONS:

Pretreatment PET cannot only potentially diagnose the extent of disease, but also may be predictive of patient survival after esophageal cancer resection. Cancer 2009. © 2009 American Cancer Society.     

Quantitative F18‐fluorodeoxyglucose positron emission tomography accurately characterizes peripheral nerve sheath tumors as malignant or benign

BACKGROUND:

Correct pretreatment classification is critical for optimizing diagnosis and treatment of patients with peripheral nerve sheath tumors (PNSTs). The aim of this study was to evaluate whether F18‐fluorodeoxyglucose positron emission tomography (FDG PET) can differentiate malignant (MPNST) from benign PNSTs.

METHODS:

Thirty‐four adult patients presenting with PNST who underwent a presurgical FDG PET/computed tomography (CT) scan between February 2005 and November 2008 were included in the study. Tumors were characterized histologically, by FDG maximum standardized uptake value (SUV_max [g/mL]), and by CT size (tumor maximal diameter [cm]). The accuracy of FDG PET for differentiating MPNSTs from benign PNSTs (neurofibroma and schwannoma) was evaluated by receiver operating characteristic (ROC) curve analysis.

RESULTS:

SUV_max was measured in 34 patients with 40 tumors (MPNSTs: n = 17; neurofibromas: n = 9; schwannomas: n = 14). SUV_max was significantly higher in MPNST compared with benign PNST (12.0 ± 7.1 vs 3.4 ± 1.8; P < .001). An SUV_max cutoff point of ≥6.1 separated MPNSTs from BPSNTs with a sensitivity of 94% and a specificity of 91% (P < .001). By ROC curve analysis, SUV_max reliably differentiated between benign and malignant PNSTs (area under the ROC curve of 0.97). Interestingly, the difference between MPNSTs and schwannomas was less prominent than that between MPNSTs and neurofibromas.

CONCLUSIONS:

Quantitative FDG PET imaging distinguished between MPNSTs and neurofibromas with high accuracy. In contrast, MPNSTs and schwannomas were less reliably distinguished. Given the difficulties in clinically evaluating PNST and in distinguishing benign PNST from MPNST, FDG PET imaging should be used for diagnostic intervention planning and for optimizing treatment strategies. Cancer 2010. © 2010 American Cancer Society.     

An approach to demonstrating cost‐effectiveness of diagnostic imaging modalities in Australia illustrated by positron emission tomography

The aim of this study was to develop a framework in which the cost‐effectiveness of new imaging technologies could be evaluated using data from other countries, while assessing the impact that any differences between the study populations and Australia may have upon the results. Publications reporting the cost‐effectiveness or therapeutic impact of positron emission tomography (PET) were re‐worked using Australian cost structures. PET was assigned a cost of $950. The effects of potential differences between the populations studied and the Australian population were evaluated by applying sensitivity analysis to those publications that describe decision tree methodology. The parameters included in the sensitivity analysis were disease prevalence and specificity of PET. The Australian cost savings per patient examined by PET were $505.50–$912.41 for investigation of solitary pulmonary nodules, $34.65–$360.03 for lung cancer staging, $550.08 for axillary staging of breast cancer, $230.75–$2301.27 for assessment of recurrent colorectal cancer and $300.24–$2069.65 for assessment of myocardial viability. Significant differences in disease prevalence and PET specificity could occur while the cost‐effectiveness of PET was preserved. Decision tree sensitivity analysis can demonstrate the cost‐effectiveness of diagnostic imaging modalities in Australia and provides indications that PET is cost‐effective for a range of clinical indications.     

18F-脱氧葡萄糖正电子发射计算机断层显像对淋巴瘤分期和预后评估的作用

 【摘要】　目的　探讨18F-脱氧葡萄糖正电子发射计算机断层显像（FDG-PET）对淋巴瘤患者分期及预后评估的作用。 方法 对初诊的41例淋巴瘤患者,化疗前和化疗4个疗程后行FDG-PET,中位随访30个月,比较化疗前FDG-PET分期和化疗4个疗程后FDG-PET结果对预后的影响。 结果 41例患者治疗前结内、外病灶的最大标准摄取值（SUVmax）分别为9.7±6.9和8.4±6.8。侵袭性非霍奇金淋巴瘤（NHL）和惰性NHL比较,结内、外病灶的SUVmax值差异有统计学意义（侵袭性NHL分别为10.3±7.5和9.1±6.5,惰性NHL分别为4.7±2.1和2.4±0.6,均P<0.05）。NHL和霍奇金淋巴瘤（HL）、B细胞和T细胞NHL、活化B与生发中心来源弥漫大B细胞淋巴瘤治疗前FDG-PET的SUVmax差异无统计学意义（P>0.05）。化疗前 22例（54 ％）患者FDG-PET检出结外器官病变;6例（15 ％）因FDG-PET发现CT等其他检查未显示的淋巴结或结外病变而提高临床分期。治疗前经FDG-PET分期为Ⅰ、Ⅱ期的患者15例（37 ％）,Ⅲ、Ⅳ期的患者26例（63 ％）。随访期间,FDG-PET分期Ⅰ、Ⅱ期的患者中1例（7 ％）因疾病进展死亡,Ⅲ、Ⅳ期的患者中6例（23 ％）因疾病进展死亡。41例患者化疗4个疗程后行FDG-PET检查,FDG-PET阴性的患者17例（41 ％）中,随访期间1例（6 ％）因疾病复发死亡,FDG-PET阳性的患者24例（59 ％）中,随访期间6例（25 ％）因疾病进展死亡。 结论　化疗前FDG-PET检查有助于对淋巴瘤患者进行准确的临床分期,化疗4个疗程后FDG-PET检查有助于评估淋巴瘤患者的预后,指导进一步治疗。     

Pancreatic cancer: Preliminary experience with sodium iodide fluorodeoxyglucose positron emission tomography in Australia

Previous studies of fluorodeoxyglucose positron emission tomography (FDG‐PET) in pancreatic cancer have used Bismuth Germinate detector systems. This preliminary Australian study aims to confirm the accuracy of FDG‐PET in pancreatic cancer using a dedicated sodium iodide (NaI) PET system. Fifteen consecutive patients underwent FDG‐PET using a GE QUEST dedicated NaI PET scanner. The indications were the characterization of a pancreatic mass seen on CT or ultrasonographic imaging (nine cases), diagnosis or exclusion of recurrent disease following surgery and adjuvant therapy (four cases) and presurgical staging of primary pancreatic cancer (two cases). The final diagnosis was determined from histology or, when no histology was available, by radiological and clinical follow up. The FDG‐PET accurately characterized eight out of nine pancreatic masses (seven were true negative, one was true positive and one was false positive). Of the four cases performed to determine recurrent disease, three were accurately diagnosed (two true negatives and one true positive). In the fourth case, PET accurately detected a liver metastasis but did not detect the local recurrence. Results in the two cases where PET was performed for preoperative staging comprised one true positive and one false negative. Sodium iodide FDG‐PET is useful in the diagnosis of pancreatic cancer, particularly in the presence of a previously detected mass.     

Coregistered whole body magnetic resonance imaging‐positron emission tomography (MRI‐PET) versus PET‐computed tomography plus brain MRI in staging resectable lung cancer

BACKGROUND:

The objective of this study was to assess whether coregistered whole brain (WB) magnetic resonance imaging‐positron emission tomography (MRI‐PET) would increase the number of correctly upstaged patients compared with WB PET‐computed tomography (PET‐CT) plus dedicated brain MRI in patients with nonsmall cell lung cancer (NSCLC).

METHODS:

From January 2010 through November 2011, patients with NSCLC who had resectable disease based on conventional staging were assigned randomly either to coregistered MRI‐PET or WB PET‐CT plus brain MRI (ClinicalTrials.gov trial NCT01065415). The primary endpoint was correct upstaging (the identification of lesions with higher tumor, lymph node, or metastasis classification, verified with biopsy or other diagnostic test) to have the advantage of avoiding unnecessary thoracotomy, to determine appropriate treatment, and to accurately predict patient prognosis. The secondary endpoints were over staging and under staging compared with pathologic staging.

RESULTS:

Lung cancer was correctly upstaged in 37 of 143 patients (25.9%) in the MRI‐PET group and in 26 of 120 patients (21.7%) in the PET‐CT plus brain MRI group (4.2% difference; 95% confidence interval, ?6.1% to 14.5%; P = .426). Lung cancer was over staged in 26 of 143 patients (18.2%) in the MRI‐PET group and in 7 of 120 patients (5.8%) in the PET‐CT plus brain MRI group (12.4% difference; 95% confidence interval, 4.8%‐20%; P = .003), whereas lung cancer was under staged in 18 of 143 patients (12.6%) and in 28 of 120 patients (23.3%), respectively (?10.7% difference; 95% confidence interval, ?20.1% to ?1.4%; P = .022).

CONCLUSIONS:

Although both staging tools allowed greater than 20% correct upstaging compared with conventional staging methods, coregistered MRI‐PET did not appear to help identify significantly more correctly upstaged patients than PET‐CT plus brain MRI in patients with NSCLC. Cancer 2013. © 2013 American Cancer Society.